1. Field of the Invention
The present invention relates to a body structure of a straddle-ride vehicle.
2. Discussion of the Background
In general, a space is provided between a body frame and a front wheel in a motorcycle. This space is adapted to be able to absorb force from front by shifting the front wheel rearward when the front wheel undergoes an unexpected excessive force.
However, the effect that the space absorbs the force from front is a secondary one. Therefore, if the force from front is further excessively large, the front wheel causes interference with the body frame. Thus, there is concern about a pitching phenomenon (hereinafter also referred to pitching) which is a rear wheel uplifting phenomenon.
For example, Japanese Patent Application Publication (KOKAI) No. 2001-82529 discloses the invention, “a suspension device of a motorcycle or the like.” Specifically, Japanese Patent Application Publication (KOKAI) No. 2001-82529 discloses a suspension device of a motorcycle or the like provided with a hydraulic damper that controls the air reaction force of a front fork to keep the gravity center of a body vehicle constant.
Japanese Patent Application Publication (KOKAI) No. 2007-269271 discloses the invention, “a shock-absorbing device-equipped vehicle and a bumper-equipped vehicle.” Specifically, Japanese Patent Application Publication (KOKAI) No. 2007-269271 discloses a technical concept in which a shock-absorbing device capable of absorbing a collision load exerted on a small-sized vehicle is mounted on the vehicle.
Japanese Patent Application Publication (KOKAI) No. 2008-80882 discloses the invention, “a front wheel suspension device.” Specifically, Japanese Patent Application Publication (KOKAI) No. 2008-80882 discloses a front wheel suspension device that suppresses pitching by lifting the front portion of a vehicle body at the time of an excessive load.
Japanese Patent Application Publication (KOKAI) No. 2002-264866 discloses the invention, “a front structure of a motorcycle.” Specifically, Japanese Patent Application Publication (KOKAI) No. 2002-264866 discloses a technical concept in which a front portion of a body frame located rearward of a front wheel is formed like the bow of a ship or a bow-like member is attached to the front portion of the vehicle frame. In this case, the leading end of the bow is made offset toward any one of the left and right from the centerline of a front wheel-width direction encountered when the front wheel is kept in a straight-ahead state. Thus, at the time of an excessive load, the steering of the front wheel is promoted to suppress pitching.
However, the suspension structure in which the special pitching-suppression structure is attached to the front fork portion or in which the gravity center of the vehicle body is lowered is structurally complicated and arranges heavy members around the front wheel. This requires advanced control in the weight distribution of a vehicle. Thus, also costs tend to increase.
If the bow-like structure is provided at the front of the vehicle, when a tire undergoes force from front, it is elastically deformed because of an elastic body and then the steering of the vehicle is started. Thus, the delay of the steering occurs. In addition, since the tire has a large friction coefficient, depending on the steering angle of a handlebar encountered when the tire undergoes force from front, the steering becomes moderate. Thus, to promote rapid and reliable steering, it is necessary to introduce an additional technical concept.